Khalil Mack didn’t even play football until his junior year of high school. He had only one Division I scholarship offer. He played for a team and in a league that are way off most fans’ radar. But Mack, a ferocious linebacker from the University at Buffalo, was the fifth player taken in the NFL draft Thursday night.

The consensus all along has been that South Carolina defensive end Jadeveon Clowney would be the top pick. But the National Football Post reported Thursday that the Houston Texans were considering — and maybe even leaning toward — taking Mack instead.

The Texans did indeed take Clowney, but Mack wasn’t far behind, being selected fifth by the Oakland Raiders and becoming just the third linebacker in history drafted in the first round by the Silver and Black.

Here’s what you need to know about him:

1. Only 1 School Recruited Him Initially, and it Wasn’t Even Buffalo

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At the beginning of Mack’s senior year in high school, it wasn’t even clear he’d receive a single Division I scholarship offer. The one team that was interested wasn’t even a member of the Football Bowl Subdivision.

The school was Liberty, which plays in the Championship Subdivision and whose assistant coach, Robert Wimberly, at the time knew he had an undervalued talent in Mack.

Khalil Mack’s recruitment, by a lone coach from an FCS school based in the Blue Ridge Mountains of Virginia, is hard to fathom in an era when Florida high school players are often well-known by colleges by the time they’re old enough to get their drivers’ permits.

When Wimberly left Liberty to join coach Turner Gill’s staff at Buffalo, the Bulls pursued Mack and landed him. He proceeded to have arguably the greatest career of any player in school history, earning All-MAC honors three times and All-America honors as a senior. (Coincidentally, Gill, who was fired as the head coach at Kansas after leaving Buffalo, is now the head coach at Liberty, and Wimberly is back at Liberty as Gill’s defensive coordinator.)

2. He Holds 2 Major NCAA Records

Mack’s 16 forced fumbles are the most in NCAA history, and his 75 tackles for loss are tied for the most in history. He broke bthe school records at Buffalo in both of those categories during his junior season and added to them substantially last year as a senior.

He also had three career interceptions and two career blocked kicks en route to being named MAC Defensive Player of the Year and being awarded the Jack Lambert Award as the nation’s top linebacker in 2013.

3. He Made Life Miserable for Ohio State QB Braxton Miller

Mack’s coming-out party came last August at Ohio State. The Buckeyes beat the Bulls 40-20, but quarterback Braxton Miller must have been having nightmares afterward about Mack, who had 9 tackles, 2.5 sacks and a 47-yard interception return for a touchdown in which he out-ran Miller down the sideline and dove into the endzone.

His impressive showing extends further than the stat line, however: Mack blitzed around the right end and suplexed Ohio State quarterback Braxton Miller causing a fumble in the third quarter, but it was called back because of an unintentional face mask penalty.

4. To Stay Humble, He Cleaned the Buffalo Locker Room

Nobody knew. You have to lead by example whether anybody knows I did it or not, it was just something that keeps you humble. I did it more than once. I wanted to help out my equipment man, Dave Borzi because he looks out for me.

5. Some Scouts Thought He Was the Best Player in the Draft

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Clowney was widely expected to go before Mack, but Mack has gotten glowing reviews from talented evaluators.

USA Today reports:

This is the deepest most uncertain draft in the past decade. Former Dallas Cowboys personnel guru Gil Brandt says Mack has a real shot to emerge the top pick and might be the better fit for Texans defensive coordinator Romeo Crennel’s 3-4 scheme.

A havoc-wreaking rush linebacker with the burst and acceleration to excel as a right defensive end in a “40” front, Mack has demonstrated the instincts, toughness, athletic ability and explosive power to line up at any linebacker position in an even or odd front and factor readily.

The reaction to the Raiders’ pick was almost unanimously positive and included a heaping of praise from ESPN analyst Bill Polian, among others.

Here’s what Polian had to say about Mack Thursday night. (Watch the video below.)

The Raiders, I think, had their dream come true. They got a defensive difference-maker who will fit perfectly into their scheme. They can have him with his hand down as an outside pass-rusher. They can stand him up as a linebacker. He can play inside or outside linebacker. He’s a tremendous physical specimen who runs exceptionally well. A potential difference-maker and the Raiders haven’t had a man like this, with especially high character and football intelligence, on their squad in some time.

CBS Sports’ Pete Prisco also had good things to say about the pick:

Khalil Mack: A no-brainer for the Raiders. He is an elite pass rusher and they need one in the worst way. GRADE: B+ http://t.co/KPxAyHqyNs